[Diagnosis of colorectal carcinoma. An update].

Colorectal cancer (CRC) is one of the most frequent tumors in western countries. More than 50% of all CRC are diagnosed at an advanced stage which precludes curative treatment. For this reason, early detection of CRC is mandatory to improve longterm outcome. Fecal occult blood testing (FOBT) once per year and subsequent colonoscopy (if the FOBT is positive) provides up to 30% decrease in mortality from CRC. Due to the fact that current data indicate a 60% reduction in CRC-associated mortality, colonoscopy has recently been approved for CRC screening by german public health insurance companies. Yet efforts in screening largely depend on patient compliance, particularly in view of cost-effectiveness. Introduction of new imaging techniques (CT-/MRI-colonography) may increase general acceptance, but clinical benefit and costs still remain to be determined in larger studies.